This invention pertains to a carton blank. More particularly, this invention pertains to a carton blank adapted for directly injection molding a closure onto the carton blank.
Consumers have come to recognize and appreciate resealable closures for containers to store, for example, liquid food products and the like. These resealable closures permit ready access to the product while providing the ability to reseal the container to prolong the life and freshness of the product. Typically, the containers or cartons are formed from a composite of paperboard material having one or more polymer coatings or layers to establish a liquid impervious structure.
In conventional packages (also referred to as cartons or containers) the closures, which are formed in a separate process and transported to the packaging process, are subsequently affixed to the cartons as part of the overall form, fill and seal operation. Typically, the closures are affixed to the partially erected carton prior to filling the carton with product.
Recently, in order to avoid the additional steps of transporting, handling and affixing the closures to the cartons, containers and processes have been developed in which closures are formed directly on the carton. That is, the closure is formed, for example, by injection molding, directly onto the carton material. In such an arrangement, a mold tool is closed over the carton (having an open area around which the closure is formed). The tool includes internal and external tool portions that are positioned at the interior and exterior regions of the carton, respectively to define a mold cavity. Plastic is then injected into the space between the internal and external tool portions to form the closure. Such an arrangement is disclosed in Lees et al., U.S. Pat. Nos. 6,467,238 and 6,536,187, which patents are commonly assigned with the present application and are incorporated herein by reference. Such an arrangement is also disclosed in copending U.S. patent application Ser. No. 10/894,759 entitled, Molding Unit for Forming Direct Injection Molded Closures, filed on even date herewith.
It has however been found that in order to properly form the closure, it is necessary to precisely position or locate the carton blank between the mold tools both longitudinally and laterally. Even the slightest of misplacement in either the longitudinal or lateral directions can result in an improperly formed or incompletely formed closure. Such a closure renders the carton unusable.
Accordingly, there exists a need for a carton and molding system for directly molding resealable closures onto the carton. Such a carton and molding system include a straightforward configuration to assure that the carton is properly aligned (longitudinally and laterally) within the molding system for plastic injection.